I do not own BioShock: Infinite. I am just doing this for my own pleasure and amusement. Un-beta'd, so please forgive any mistakes.

The first time Robert noticed the tapping of Rosalind's fingers within twenty minutes of living in her world. This was, of course, after a day of being so sick and disoriented from crossing into her world. Twenty four hours and twenty minutes and I have discovered something new about myself…my sister…who is me. Rosalind thrust a clean handkerchief below his nose as blood streamed. Perhaps it was best not to think of such differences for a while.

It took a couple weeks past that point for Robert to think on his sisters' fingers without getting a migraine and needing yet another fresh kerchief. It interested him because it was a trait that he had never picked up, not even when he was bored. He would tap his lips in thought, which Rosalind also would do while they looked over their blackboards covered in complex equations. A constant between them. The drumming on the table on the other hand…

It took yet another week to realize that the patterns were not just the cascading of pinky to thumb. There were variations. Sometimes fingers were held down longer while others were beat out in sharp motions. Robert noticed when Rosalind was agitated her brow would furrow and her fingers would move quickly, tapping a sharp staccato on her arm. Other times, most often when she was trying to sooth Robert through a migraine or pressing a cloth to him to staunch the flow of blood from his nose, her fingers would be softer. It wasn't patterns Rosalind was drawing, just the soft tap tap tap of her fingertips on his shoulder. Sometimes they were so soft that he wasn't entirely sure she was still there until her fingers would once again press into him reassuringly.

No, it wasn't until a month later that Robert realized what it all meant. While enjoying a relaxing evening in their front parlor one grey Sunday, he grew tired of the patter of rain on the window and the sharp cracks of the fire. Glancing at his sister who was sitting by the fire with her eyes closed and breathing soft, he quietly moved to the record player and began looking through the tiles of their collection. After settling on a collection of Beethoven piano works, Robert returned to his chair and took up his newspaper again. He knew Fur Elise from his constant listening of the record in his old world. He hummed along as he thumbed through the paper. As the music picked up he glanced over the paper at Rosalind to see if she was being roused. She sat in the same position as earlier, but her hands kept in perfect time to the recording that was being played, matching the speed and the striking of the notes. Robert set aside his paper and watched her fingers dance along her lap as if she were at a keyboard and not in a chair by the fire.

"Well that is interesting…" Robert breathed. His voice seemed to stir Rosalind from her world.

"I am allowed to know things other than the sciences brother," She said as she continued to play the air in front of her. "I would have figured you knew that a woman's education includes the arts. I was…we were…dreadful artists so mother let me play the piano."

Robert nodded; entranced by her slender fingers striking the air in front of her. "Can you play anything else?" Rosalind snorted.

"I'm not a one trick pony. Fur Elise isn't a wholly challenging piece. I daresay if we had a piano, I could show off more, but we don't need any more clutter in this house do we?" Robert coughed a little, trying to fend off the headache that was beginning to form.

"We could move some of the chalkboards into the kitchen." He began nonchalantly. "Besides, the room feels empty without an instrument taking it up. Mother did play the harp, and the piano beside it always made the room feel cozy." Robert tapped at his lip in thought, wincing when it came back bloody. He was doing so well earlier, he thought. Rosalind sighed, getting up while he placed his handkerchief to his nose.

"Rest dear brother. I don't want to be the cause of your problems any more than I already am." She shooed him upstairs and then turned and looked at the room. Perhaps Comstock had a piano she could use for a time.

—-

Robert didn't mention Rosalind's piano playing skills after that day and even a week later nothing had been said about the piano discussion. She seemed to believe that her piano playing was too much of a difference between them and wasn't willing to call his memories into conflict. He noticed that she didn't tap on her arm anymore, preferring to mirror him when she was in deep thought. Robert couldn't help but feel disappointed. True, they were in essence the same person, but their differences, especially the ones he saw in her were just fascinating. Not only could Rosalind play piano (rather well, as far as he could recognize), but she enjoyed her tea with sugar, she prefered to sleep curled up in on herself, she always took a break at a quarter to four to get some fresh air outside, even if it was raining. He had also spent some time trying to count the freckles on her nose, a task that proved more challenging than he had originally thought.

"Robert."

"Hm? Yes?"

"Have you found something interesting out of that window?" Rosalind's voice held a hint of amusement. He turned to look at her, noting her sleeves were rolled up and she seemed to be breathing heavier than usual. Her hair was beginning to come unpinned as well and her skirt was more rumpled than it was when he last saw her an hour ago.

Nothing as interesting as you, Robert thought to himself as he cleared his throat. "If I said the cloud formations that are developing to the east, would you believe me?"

"I would not." She replied, the corner of her mouth rising into a half smile.

"Then there is nothing of interest out there for me, dear sister."

"Hm, well perhaps I can show you something of interest in the parlor then." She inclined her head and left the room. Robert followed, unsure of what he was to find. When he entered the room and noted the piano pushed against the wall opposite the fireplace, he could say with certainty that it wasn't what he had been expecting.

"I got it from Comstock," Rosalind explained, running her hand over the covered keys. "He seemed to have a piano in every parlor of his floating mansion, and it was easy to get him to part with one. I'm surprised you didn't hear me moving it into position with the movers" She lifted the cover and struck the center key, letting the note hang in the room. "The response is good and it has been recently tuned, but I do warn you brother, I haven't played in over a year. Your ears may be less offended by putting on a record."

Robert chuckled and sat on the chair closest to the piano. "I'm sure that whatever sounds you can draw out of it would be far better than my own attempt." Rosalind nodded toward him and sat down on the bench, flexing her fingers.

"You may want to close your eyes, so you don't have conflicting memories," She said placing her fingers lightly on the keys. "I would hate to have you start bleeding during my performance." He nodded and let his eyes close. He heard her take a breath, nervously, and softly, firmly, Rosalind began to play.

It was not Fur Elise, like Robert was expecting, but another Beethoven piece. Piano Sonata No. 15. Better known as the "Moonlight Sonata," he thought. We do prefer the melancholy, my sister and I. He let the music wash over him. It was far from perfect, and he could tell his sister was both rusty and nervous. A chord was struck wrong, she lingered on notes trying to divine the next passage. When the first movement was finished Robert let the chord hang in the air for a moment before quietly applauding.

"You know better than to clap in between movements," Rosalind grumbled softly. He smiled benignly, imagining the scowl that was likely on her face.

"Just providing some encouragement. Please, continue."

"I don't remember the second movement in the slightest," She said with a sigh, "I hope you don't mind me skipping to the finale."

"This is your concert Rosalind. You're the one to dictate the music." Robert settled in, waiting for his sister to begin again. Cracking her knuckles, Rosalind paused for another breath and then pounded the beginning chord. He jumped and swore he heard her laugh lightly. Any other noise that Robert could have heard was soon swallowed up by the mad fury of the piano. After a moment he cracked open his eyes and chanced looking at her. There were so many notes crowding for space, but Rosalind played deftly. Her fingers seemed to barely touch the keys before continuing on. He looked at her face and saw the fierce concentration she usually reserved for their hardest equations. He shifted slowly so as not to alert her and leaned even closer to the piano, admiring the delicate curve of her hand as she moved from one phrase to another. It seemed all too soon to him that Rosalind finished the song with a flourish of her hands. There was a long moment where the only sound was her heavy breathing and Robert realized that he was leaning towards her, eyes very obviously not closed.

"I thought I said you should keep your eyes closed while I played." Rosalind said, panting slightly.

"I couldn't help myself," Robert murmured, looking into her eyes shyly. "Your playing was wonderful, sister." She sighed in response. Hoping he hadn't upset her, he got up and sat next to her on the bench, causing her to move herself to give him room. They sat in silence for a moment, shoulders touching.

"I don't like you being in pain, and I took a calculated risk in even introducing the piano into our equation here," Rosalind said softly. She lightly rested her hand on the keys and began playing Twinkle, Twinkle, Little Star. "I just thought…You seemed interested a week ago when you noticed my nervous habit." She laughed at her comment. "A silly nervous habit. You know I had done so well for so long. I learned to not be nervous around others. My peers back in college would have eaten me alive had they noticed. But around you," Robert swallowed, his throat becoming more dry than he would have liked, "I am with myself, and I don't have to hide my feelings, even if they are just silly nerves."

"I think I understand how you feel," Robert said, placing his hand lightly on top of hers on the piano, stilling it. "And I thank you, fair Rosalind, for allowing me to intrude on you." He lifted her hand and brushed his lips against her fingers, looking into her eyes that were the same cerulean as his own. "Your playing was beautiful."

Thank you for reading. Favorite, review, follow me on tumblr (musicaljinx), or just have a lovely day!